The present invention relates to a vehicular knob switch apparatus called stalk switch and more particularly to a vehicular knob switch apparatus having a cylindrical housing and a plurality of operating means, including a rotary operating knob, disposed in the housing.
Generally, in the vicinity of a vehicular steering column there is provided a vehicular knob switch apparatus called stalk switch for controlling the motion of windshield wipers, headlights, etc. The vehicular knob switch apparatus comprises a cylindrical housing supported pivotably on the steering column side, an operating knob attached to the housing rotatably from the exterior, and a rotary detector such as a rotary volume which is operated by a rotational operation of the operating knob. By operating the housing pivotally or by rotating the operating knob there are performed on-off switching of a wiper device, change-over in strength and in intermittent motions of the wiper device, on-off switching of headlights, etc.
According to an example of a known vehicular knob switch apparatus, a printed circuit board is enclosed in a housing so as to be orthogonal to the axis of an operating knob, and a rotary shaft of a rotary detector mounted on the printed circuit board is rotated by the operating knob. In the vehicular knob switch apparatus thus constructed, when the operating knob is rotated in either forward direction or reverse direction, the rotary shaft rotates in interlock with the operating knob, so that a relative position between a brush of the rotary detector and a pattern changes, whereby an electric signal corresponding to the rotating motion of the operating knob is outputted to the exterior.
In vehicular knob switch apparatuses, key tops and the like are disposed at arbitrary positions of the housing separately from the operating knob to operate not only the rotary detector but also other electric components, thereby attaining multi-function. In the above conventional vehicular knob switch apparatus, however, a printed circuit board with the rotary detector mounted thereon is enclosed in the housing in an orthogonal relation to the axis of the operating knob. Therefore, it is difficult to mount other electric components on the printed circuit board and it is required to disposed another printed circuit board within the housing, thus giving rise to the problem that the number of components used and the size of the entire apparatus become larger.